Vibration attenuation systems are used in a variety of situations including mechanically isolating vibrating devices from external structures and isolating vibration sensitive instruments from external vibration sources. For example, in the submarine environment, it is often desired to attenuate vibrations from compressors, motors and other vibrating devices for a more quiet operation. In certain aerospace applications, it is important to isolate remote sensing, imaging and other optical bench instruments from vibration sources. Other applications where isolation from vibration is important include cryo-cooler applications. In such vibration attenuation systems it will therefore be appreciated that the driving source may be a vibrating device or an ambient or external vibration source. Moreover, the attenuation system may support the vibration source to isolate the source from an external structure, or the attenuation system may support a structure and isolate the structure from an external source of vibration.
Over the years, various techniques and systems have been developed for attenuating vibratory energy. For example, vibration isolation mounts including resilient materials for attenuating vibrations have been positioned between a support structure and a vibration source for mechanically isolating the vibration source from the structure. Another type of vibration attenuation system that has been proposed involves the use of a shape memory alloy. For example, shape memory alloys have been embedded within polymeric sheets that support vibrating devices. In principle, by heating or cooling the shape memory alloy, the stiffness of the sheet can be controlled to avoid undesired resonances. Unfortunately, due to the interaction of the elasticity of the sheet material with the variable elasticity of the shape memory alloy, as well as the limited variation in shape memory alloy elasticity, such vibration attenuation systems have provided a limited degree of vibration attenuation or frequency response in certain cases.